Control for hydraulic couplings



1949' J. D. MQCRACKEN 2,459,734

CONTROL HYDRAULIC COUPLINGS Filed Aug. 3]., 1942 ,1 YIFUK BULB IN OIL LINE FROM MASTER REGULATOR 0R FUEL REGULA OR graze/MM JBZYC (hm/Em Patented Jan. 18, 1949 UNITED STATES PATENT OFFICE CONTROL FOR HYDRAULIC COUPLINGS James D. McCracken, Chicago, IlLfassignor to Askania Regulator Company, Chicago, 111., a corporation of Illinois Application August 31, 1942, Serial No. 456,806

3 Claims. (CI. 6054) is connected in series with a cooler 6 and a pump 1 by means of pipes, as for instance pipe 8 having a valve!) therein and pipe ill with a vapor in accordance with changes in the temperature of the fluid in the coupling. The series circuit of pipe communications for the coupling, cooler and pump include two valves automatically adjustable, one connected responsive to impulses from a master regulator and abubbling device, and the other responsive to circulation temperature.

Other aims and advantages of the invention will appear in the specification, when considered in connection with the accompanying drawing,

wherein the figure is a diagrammatic illustration of a control system embodying the invention.

The usual circuit for a hydraulic coupling control embodies a cooler connected in series with the coupling and oil is added to or taken away from the working circuit through a parallel circuit including the pump and the sump, and valves controlled by the master regulator which responds to a condition such as steam pressure in a boiler wherein the coupling is arranged -between the motor and the fan which supplies combustion supporting air for the boiler furnace.

The coupling fluid, in the usual circuit, circulates at a rate which depends approximately.

on the load imposed upon'the coupling. It is l scooped out of the coupling and forced through a cooler ad back into the coupling. It leaks through ports into the scoop chamber at a rate which depends on the size and number of leak ports and on the mean depth of the oil in the working chamber. For any particular load, there is a definite rate of circulation which is not varied. As the temperature of the oil changes, the coupling efllciency varies. The present invention, therefore, provides means for maintaining the oil temperature substantially constant by controlling the rate of circulation of the oil through the series circuit.

Referring particularly to the drawing, the system is shown as being connected to operate a hydraulic coupling which, incidentally, may be employed to rotate a fan (not shown) for supplying combustion air to a furnace, as shown in copending application Ser. No. 446,750, filed June bulb H and valve l2. The series connection for the hydraulic fluid thus involves the coupling, the cooler and the pump.

The valve 9 is shown as being adjusted by means of a piston 13 movable in a cylinder 14 'connected by pipes l5 and Hi to a well known jet pipe relay having a jet pipe I! and a ratio slider I 8. A pressure responsive diaphragm I9 is connected to a master regulator (not shown) by means of a pipe and a second pressure responsive diaphragm 2| is connected by pipe 22 to a bubbling device 23. The two diaphragms l9 and 2| thus act on the jet pipe I! and move the latter in response to pressures or to differential pressures on said diaphragms.

The bubbling device 23 receives its air under pressure from a supply pipe 24 and this device is submerged in an oil sump or container 25. A pipe 26 from the pump 1 acts to draw oil from the sump and pipe 21 permits oil to return to the sump after completing the circuit. A third pipe 28 having a relief valve 29 is adapted to act as a safety device in case valve 9 is not sufiiciently open to take care of the oil forced from the pump 1.

The vapor bulb I I transmits its expanded fluid to a flexible tube 30 by means of pipe 3|, and this tube acts, by means of rod 32, on a jet pipe 33 counteracted by a spring 34 adjustable as to its force by means of the device 40. The hydraulic fluid from the jet pipe 33 enters both or one or the other of the pipes 35 and 36 to control a piston 31 in a cylinder 38. The piston 31 is connected to control or adjust the valve [2.

In the operation of the system, it will be understood that the pump 1 supplies oil continuously to the coupling 5 in response to a load. The jet pipe regulator l1 controls thevalve 9 in response 12, 1942, now Patent No. 2,392,300. The coupling to changes in the load or the condition. The valve l2 remains partially opened and permits return flow of the oil picked up by the scoop tube in the coupling through the pump circuit and the cooler. As the temperature of the oil varies, the vapor bulb ll operates the regulator 33 to vary the position of the valve I2. The arrangement is such that, when the temperature increases, the valve will be opened wider to permit the return flow to increase. Lowering of the level in the coupling and the resulting rise in the level of the oil in the sump 25 will cause the regulator II to further open the valve 9. When the coupling load increases, which calls for an increase in the supply of oil tothe coupling. the regulator l'l will cause the valve I to open more until the level in the sump 25, is at a new reduced level which corresponds with the new load. Since the oil circulation is limited by the valve ii. the oil in the coupling will increase. The oil level and the valve 9 will cycle for a time or two and then flnd the equilibrium position. Decrease in the load will reverse the operation; that is to say, valve I will close more or throttle until the sump level increases to the new appropriate level and will then cycle once or twice until the valve 9 has found its equilibrium position again. If the-valve open the valve 9 and keep the sump level constant and permit a greater rate of circulation. It will therefore be understood that the valve 12 functions to control the circulation. Obviously, i may be employed to control the load and the valve 9 can control the circulation. Thus, the load control and the circulation control will both be fully automatic;

It is possible to place the valve 12 and bulb II and its associated elements in the pipe 8 between the pump 1 and the cooler 6, and the valve 9 together with its associated parts may be connected in the pipe it between the coupling 5 and pump I.

Obviously, the present invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly, since theyv may be employed advantageously in various combinations and subcombinations.

What is claimed is:

1. In combination with a hydraulic coupling having a pipe circuit for supplying and returning the operating fluid, a pump and a cooler in said circuit connected in series with thecoupling; a sump carrying the operating fluid into which excess returned fluid is delivered; a supply valve in the circuit between the pump and the cooler; an automatic regulator for said valve having an air bubbling device connected to said sump to operate the regulator in response to variations of air pressure in the air bubbling pipe; and a temperature controlled valve in the fluid return portion of said circuit responsive to the temperature of thereturning fluid to control the circulation of fluid through the cooler.

.-2. The combination set forth in claim 1, wherein impulse means responsive to a condition to be controlled is also connected to said regulator and acts in opposition -to the impulses derived from air bubble device.

3. In combination with a hydraulic coupling having a pipe circuit for supplying and returning the operating fluid, a pump and a cooler in said circuit connected in series with the coupling; a sump carrying the operating fluid into which excess return fluid is delivered; a supply valve in the circuit between the pump and the cooler; an automatic regulator for said valve; impulse means, responsive to changes in the' level of the fluid in said sump acting upon said regulator;

opposing impulse means acting on said regulator.

in response to impulses derived from a condition to be controlled, whereby the supply valve may be operated to maintain a controlled condition substantially constant; a fluid return valve also arranged in the fluid circuit; and means responsive to the temperature of the returning fluid connected to operate said return valve.

JAMES D. McCRACKEN.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS 

